Electroplating nickel



Patented Aug. 26, 1947 Ernest W. Schweikher, Cleveland Heights, Ohio,

assignor to E. I. do P,ont de Nemours & Company, Wilmington, ncl a corporation of Dela- No Drawing. Application June. 10,

Serial No. 397,383

6. Claims. (Cl. 202-49) Thi invention relates to the electrodeposition of nickel and is more particularly directed to nickel plating compositions, nickel plating baths, and nickel plating processes wherein there is employed a'compositionas follows: I

. Grams per liter Nickel chloriden' 225 to 275 Nickel sulfate 15' to 60 Boric acid 45 to 60 Metasulfobenzaldehyde.-; s 4 to It has previously been proposed to use asulfobenzaldehyde as an addition agent for nickel plating. It has also been proposed recently to use nickel sulfate in nickel chloride baths the ratio of chloride anion to sulfate anion falling within the range from 5: 1 to 1.

It is an objector this invention to provide compositions, baths, and processes by the use of which there may be obtained bright nickel deposits of excellent character. It isafurther object to provide compositions, baths, and processes which require a minimum of maintenance and which over considerable periods of time will consistently produce deposits of excellent and uniform character. It is a still further object to provide nickel plating compositions, baths, and processes by the use of which there may be obtained nickel deposits which are brilliant and ductile even over long periods of operation. Still further objects of this invention will become apparent hereinafter.

The foregoing and other objects are attained by the use of a bath composition as follows:

Nickel chloride grams per liter 225 to 2'75 Nickelsulfate do 15 to 60 Boric a d 45 to 60 Metasulfobenzaldehyde do 4 to 10 pH r 2.0 to 4.0

. Nickel chloride (NiClz-SHzO) 1 Example I A nickel plating bathwas made up as follows:

grams per liter 250 ,Nicke lsulfate (NiSO4'7H2 O) do 15 Boric acid (HaBOa) do 50 Metasulfobenzaldehyde do 4 pH 3.5 Temperature 50 C.

Brilliant nickel deposits were made from the bath of this example at a current density of about 35 amperes per square foot and a number of artciles which had previously been copper plated were given'pit-free, ductile deposits which without further buffing or polishing served admirably as a base surface for chromium plating.

The temperature of the baths of this invention durlng'operation may vary but it will be preferred to use temperatures between about 45 and 55 C. Deposits of desirable character will I have found that metasuliobenzaldehyde in long periods of time with every minimum of maintenance. Each component in the proportions recited cooperates with the others to produce the unexpected results of the invention- A preferred illustrative'bath of the present in vention is described in the following example:

ordinarily be produced at current densities from about 5 to amperes per square foot.

In the use of the bath of this example there was employed electrolytic cathode nickel as anodes. It is one of the advantages of this type of bath that cathode nickel may be used as anode without any special treatment.

. While reierence is made herein to the addition of metasulfobenzaldehyde, it will be understood that the addition agents may be added to a plating bath in the 'form of various salts. It may, for instance, be added to the bath in the form of a sodium, potassium, ammonium, or nickel salt. Whether or not the sulfobenzaldehyde i present in the bath as a salt or as a free acid will depend upon the pH of the bath and consequently for the purposes of this invention either the acid or a suitable salt may be used interchangeably. As a matter of fact, the metasulfobenzaldehyde was added in the composition of the above example as the nickel salt.

The baths of this invention may be modified by the inclusion of additions known to benefit electroplating baths. The addition agents of the Lutz-Westbrook Patent 1,818,229 may be used and --there may similarly be used the addition agents of Schlotter 1,972,693, Waite 2,112,818, Flett 2,195,409, Pine 2,029,386 and 2,029,387, Lynn,

Harshaw, and Long 2,198,267 and 2,198,268, and Harshaw and Long 2,125,229. While such additions or mixtures of such addition agents may be made to the baths of this invention it will ordinarily be found most desirable not to use other bath-improving agents and according to the preferred practices of this invention there is employed an electroplating bath consisting essentially of the following at the proportions shown:

Nickel chloride grams per liter 225 to 275 Nickel sulfate; ..do 15 to 60 Boric acid do 45 to 60 Metasulfobenzaldehyde do 4 to PH 2.0 to 4.0 Temperature 50 C.

solving the various ingredients simultaneously or individually in water. a

While I have shown certain compositions, baths, and processes, it will be understood that one skilled in the art may readily devise numerous similar compositions, baths, and processes without departing from the spirit of the invention.

I claim:

1. An aqueous nickel plating bath comprising:

Grams per liter Nickel chloride 225 to 275 Nickel sulfate to 60 Boric acid 45 to 60 Metasulfobenzaldehyde 4 to 10 2. An aqueous nickel plating bath comprising substantially:

Grams per liter Nickel chloride (NiC12'6H2O) 250 Nickel sulfate (NiSO4-7H2O) 15 Boric acid (H3BO3) 50 Metasulfobenzaldehyde 4 3. In a process for the electrodeposition of nickel, the step comprising effecting electrodeposition from an aqueous nickel plating bath comprising:

Grams per liter Nickel chloride 225 to 275 Nickel sulfate 15 to Boric acid 45 to 60 Metasulfobenzaldehyde 4 to 10 4. In a process for the electrodeposition of nickel, the step comprising effecting electrodeposition from an aqueous nickel plating bath comprising substantially:

Grams per liter Nickel chloride (NlClZGHZO) 250 Nickel sulfate l5 Boric acid 50 Metasulfobenzaldehyde 4 5. A nickel plating composition which upon addition of water will yield a solution of the following in the indicated proportions:

Grams per liter Nickel chloride 225 to 2'75 Nickel sulfate 15 to 60 Boric acid 45 to 60 Metasulfobenzaldehyde 4 to 10 6. A nickel plating composition which upon addition of water will yield a solution of the following in the indicated proportions Grams per liter Nickel chloride (NiClz-GHzO) 250 Nickel sulfate (NiSO4-7H2O) 15 Boric acid (HsBOs) 50 Metasulfobenzaldehyde 4 ERNEST W. SCHWEIKHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,191,813 Brown Feb. 27, 1940 2,198,267 Lind et al Apr. 23, 1940 OTHER REFERENCES Physical Review, Second Series (1925), volume 26, pages 390 and 396. 

